1. Field of the Invention
The present invention is related to an exhaust emission control device in an internal combustion engine and a heat engine for automobile, marine or stationary use.
2. Description of the Related Art
In recent years, there is a trend that regulation of exhaust gas of internal combustion engines for automobiles, etc. (hereafter referred to as engines) is intensified. Particularly, the regulation of NOx(nitrogen oxides) and PM(particulate matter) in exhaust gas of diesel engines and regulation of NOx(nitrogen oxides) and HC(unburned gas) in exhaust gas of gasoline engines has been intensified.
In the prior art, generally exhaust emission control for reducing emissions such as HC, NOx, and PM has been performed by allowing the exhaust gas to pass through an after-treatment device, which is provided with catalyst and installed in the exhaust system, after the exhaust gas is discharged from the engine cylinder. Further, there is proposed a device in which catalyst is coated at least on a part of the wall of the combustion chamber formed by the inside surface of cylinder, inside surface of cylinder head, and top face of piston as shown in FIG. 1 of JP 5-86863, not that an after-treatment device is installed in the exhaust system.
However, there has not been disclosed an art which makes the most use of the technique supporting catalyst on the surface of combustion chamber wall by combining the technique of supporting catalyst on the surface of combustion chamber wall as shown in FIG. 1 of JP 5-86863 and the technique of controlling fuel injection through the fuel injection equipment or controlling inlet and exhaust valve timing through the valve driving gear of the engine.